RESUMO
Inhibition of intracellular nicotinamide phosphoribosyltransferase (NAMPT) represents a new mode of action for cancer-targeting antibody-drug conjugates (ADCs) with activity also in slowly proliferating cells. To extend the repertoire of available effector chemistries, we have developed a novel structural class of NAMPT inhibitors as ADC payloads. A structure-activity relationship-driven approach supported by protein structural information was pursued to identify a suitable attachment point for the linker to connect the NAMPT inhibitor with the antibody. Optimization of scaffolds and linker structures led to highly potent effector chemistries which were conjugated to antibodies targeting C4.4a (LYPD3), HER2 (c-erbB2), or B7H3 (CD276) and tested on antigen-positive and -negative cancer cell lines. Pharmacokinetic studies, including metabolite profiling, were performed to optimize the stability and selectivity of the ADCs and to evaluate potential bystander effects. Optimized NAMPTi-ADCs demonstrated potent in vivo antitumor efficacy in target antigen-expressing xenograft mouse models. This led to the development of highly potent NAMPT inhibitor ADCs with a very good selectivity profile compared with the corresponding isotype control ADCs. Moreover, we demonstrateâto our knowledge for the first timeâthe generation of NAMPTi payload metabolites from the NAMPTi-ADCs in vitro and in vivo. In conclusion, NAMPTi-ADCs represent an attractive new payload class designed for use in ADCs for the treatment of solid and hematological cancers.
Assuntos
Antineoplásicos , Imunoconjugados , Neoplasias , Nicotinamida Fosforribosiltransferase , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antígenos B7 , Linhagem Celular Tumoral , Humanos , Imunoconjugados/química , Imunoconjugados/farmacologia , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Nicotinamida Fosforribosiltransferase/química , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Several antibody-drug conjugates (ADCs) have failed to achieve a sufficiently large therapeutic window in patients due to toxicity induced by unspecific payload release in the circulation or ADC uptake into healthy organs. Herein, we describe the successful engineering of ADCs consisting of novel linkers, which are efficiently and selectively cleaved by the tumor-associated protease legumain. ADCs generated via this approach demonstrate high potency and a preferential activation in tumors compared to healthy tissue, thus providing an additional level of safety. A remarkable tolerance of legumain for different linker peptides, including those with just a single asparagine residue, together with a modifier of the physicochemical metabolite profile, proves the broad applicability of this approach for a tailored design of ADCs.
Assuntos
Imunoconjugados/química , Cinesinas/antagonistas & inibidores , Animais , Cisteína Endopeptidases/metabolismo , Sistemas de Liberação de Medicamentos , Humanos , Camundongos , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Pró-Fármacos , Relação Estrutura-Atividade , Neoplasias Urológicas/tratamento farmacológico , UrotélioRESUMO
Many antibody-drug conjugates (ADCs) have failed to achieve a sufficient therapeutic window in clinical studies either due to target-mediated or off-target toxicities. To achieve an additional safety level, a new class of antibody-prodrug conjugates (APDCs) directed against different targets in solid tumors is here described. The tumor-associated lysosomal endopeptidase legumain with a unique cleavage sequence was utilized for APDC metabolism. Legumain-activatable APDCs were as potent as their cathepsinâ B-activatable analogues. The peptide sequence susceptible to legumain cleavage was optimized for further discrimination of the formation of active metabolites within tumor cells versus healthy tissues, leveraging different tissue-specific legumain activities. Optimized APDCs with slow legumain-mediated conversion reduced preclinically the levels of active metabolite in healthy organs while retaining high activity against different TWEAKR- and B7H3-expressing tumors.
Assuntos
Anticorpos/química , Antineoplásicos/química , Cisteína Endopeptidases/metabolismo , Imunoconjugados/química , Cinesinas/antagonistas & inibidores , Oligopeptídeos/química , Pró-Fármacos/química , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/metabolismo , Antígenos B7/genética , Antígenos B7/imunologia , Antígenos B7/metabolismo , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Imunoconjugados/administração & dosagem , Imunoconjugados/metabolismo , CamundongosRESUMO
The number of cytotoxic payload classes successfully employed in antibody-drug conjugates (ADCs) is still rather limited. The identification of ADC payloads with a novel mode of action will increase therapeutic options and potentially increase the therapeutic window. Herein, we describe the utilization of kinesin spindle protein inhibitors (KSPi) as a novel payload class providing highly potent ADCs against different targets, for instance HER-2 or TWEAKR/Fn14. Aspects of technical optimization include the development of different linker attachment sites, the stabilization of ADC linkage to avoid payload deconjugation and finally, the tailor-made design of active metabolites with a long lasting intracellular exposure in the tumor matching the mode of action of KSP inhibition. These KSPi-ADCs are highly potent and selective inâ vitro and demonstrate inâ vivo efficacy in a broad panel of tumor models including complete regressions in a patient-derived urothelial cancer model.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Imunoconjugados/química , Imunoconjugados/farmacologia , Cinesinas/antagonistas & inibidores , Pirróis/química , Pirróis/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Descoberta de Drogas , Humanos , Imunoconjugados/uso terapêutico , Neoplasias/tratamento farmacológico , Pirróis/uso terapêuticoRESUMO
Introduction: The development of bioconjugates for the targeted delivery of anticancer agents is gaining momentum after recent success of antibody drug conjugates (ADCs) in the clinic. Smaller format conjugates may have several advantages including better tumor penetration; however, cellular uptake and trafficking may be substantially different from ADCs. To fully leverage the potential of small molecule drug conjugates (SMDCs) with potent binding molecules mediating tumor homing, novel linker chemistries susceptible for efficient extracellular activation and payload release in the tumor microenvironment (TME) need to be explored. Methods: We designed a novel class of SMDCs, which target αvß3 integrins for tumor homing and are cleaved by neutrophil elastase (NE), a serine protease active in the TME. A peptidomimetic αvß3 ligand was attached via optimized linkers composed of substrate peptide sequences of NE connected to different functional groups of various payload classes, such as camptothecins, monomethyl auristatin E, kinesin spindle protein inhibitors (KSPi) and cyclin-dependent kinase 9 inhibitors (CDK-9i). Results: NE-mediated cleavage was found compatible with the diverse linker attachments via hindered ester bonds, amide bonds and sulfoximide bonds. Efficient and traceless release of the respective payloads was demonstrated in biochemical assays. The newly designed SMDCs were highly stable in buffer as well as in rat and human plasma. Cytotoxicity of the SMDCs in cancer cell lines was clearly dependent on NE. IC50 values were in the nanomolar or sub-nanomolar range across several cancer cell lines reaching similar potencies as compared to the respective payloads only in the presence of NE. In vivo pharmacokinetics evaluating SMDC and free payload exposures in rat and particularly the robust efficacy with good tolerability in triple negative breast and small cell lung cancer murine models demonstrate the utility of this approach for selective delivery of payloads to the tumor. Discussion: These results highlight the broad scope of potential payloads and suitable conjugation chemistries paving the way for future SMDCs harnessing the safety features of targeted delivery approaches in combination with NE cleavage in the TME.
RESUMO
Regulatory T cells (Tregs) are known to facilitate tumor progression by suppressing CD8+ T cells within the tumor microenvironment (TME), thereby also hampering the effectiveness of immune checkpoint inhibitors (ICIs). While systemic depletion of Tregs can enhance antitumor immunity, it also triggers undesirable autoimmune responses. Therefore, there is a need for therapeutic agents that selectively target Tregs within the TME without affecting systemic Tregs. In this study, as shown also by others, the chemokine (C-C motif) receptor 8 (CCR8) was found to be predominantly expressed on Tregs within the TME of both humans and mice, representing a unique target for selective depletion of tumor-residing Tregs. Based on this, we developed BAY 3375968, a novel anti-human CCR8 antibody, along with respective surrogate anti-mouse CCR8 antibodies, and demonstrated their in vitro mode-of-action through induction of potent antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) activities. In vivo, anti-mouse CCR8 antibodies effectively depleted Tregs within the TME primarily via ADCP, leading to increased CD8+ T cell infiltration and subsequent tumor growth inhibition across various cancer models. This monotherapeutic efficacy was significantly enhanced in combination with ICIs. Collectively, these findings suggest that CCR8 targeting represents a promising strategy for Treg depletion in cancer therapies. BAY 3375968 is currently under investigation in a Phase I clinical trial (NCT05537740).
Assuntos
Receptores CCR8 , Linfócitos T Reguladores , Microambiente Tumoral , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Receptores CCR8/imunologia , Receptores CCR8/antagonistas & inibidores , Animais , Camundongos , Humanos , Microambiente Tumoral/imunologia , Microambiente Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Feminino , Citotoxicidade Celular Dependente de Anticorpos , Depleção Linfocítica , Linhagem Celular Tumoral , Fagocitose/efeitos dos fármacos , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêuticoRESUMO
Double-hit diffuse large B-cell lymphoma (DH-DLBCL) is an aggressive, and often refractory, type of B-cell non-Hodgkin lymphoma (NHL) characterized by rearrangements in MYC and BCL2. Cyclin-dependent kinase 9 (CDK9) regulates transcriptional elongation and activation of transcription factors, including MYC, making it a potential targeted approach for the treatment of MYC+ lymphomas. Enitociclib is a well-tolerated and clinically active CDK9 inhibitor leading to complete metabolic remissions in 2 of 7 patients with DH-DLBCL treated with once weekly 30 mg intravenous administration. Herein, we investigate the pharmacodynamic effect of CDK9 inhibition in preclinical models and in blood samples from patients [DH-DLBCL (n = 10) and MYC+ NHL (n = 5)] treated with 30 mg i.v. once weekly enitociclib. Enitociclib shows significant regulation of RNA polymerase II Ser2 phosphorylation in a MYC-amplified SU-DHL-4 cell line and depletion of MYC and antiapoptosis protein MCL1 in SU-DHL-4 and MYC-overexpressing SU-DHL-10 cell lines in vitro. Tumor growth inhibition reaching 0.5% of control treated SU-DHL-10 xenografts is achieved in vivo and MYC and MCL1 depletion as well as evidence of apoptosis activation after enitociclib treatment is demonstrated. An unbiased analysis of the genes affected by CDK9 inhibition in both cell lines demonstrates that RNA polymerase II and transcription pathways are primarily affected and novel enitociclib targets such as PHF23 and TP53RK are discovered. These findings are recapitulated in blood samples from enitociclib-treated patients; while MYC downregulation is most robust with enitociclib treatment, other CDK9-regulated targets may be MYC independent delivering a transcriptional downregulation via RNA polymerase II. SIGNIFICANCE: MYC+ lymphomas are refractory to standard of care and novel treatments that downregulate MYC are needed. The utility of enitociclib, a selective CDK9 inhibitor in this patient population, is demonstrated in preclinical models and patients. Enitociclib inhibits RNA polymerase II function conferring a transcriptional shift and depletion of MYC and MCL1. Enitociclib intermittent dosing downregulates transcription factors including MYC, providing a therapeutic window for durable responses in patients with MYC+ lymphoma.
Assuntos
Quinase 9 Dependente de Ciclina , Linfoma Difuso de Grandes Células B , RNA Polimerase II , Humanos , Quinase 9 Dependente de Ciclina/antagonistas & inibidores , Regulação para Baixo , Proteínas de Homeodomínio/genética , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteínas Proto-Oncogênicas c-myc/genética , RNA Polimerase II/genéticaRESUMO
The emerging field of small-molecule-drug conjugates (SMDCs) using small-molecule biomarker-targeted compounds for tumor homing may provide new perspectives for targeted delivery. Here, for the first time, we disclose the structure and the synthesis of VIP236, an SMDC designed for the treatment of metastatic solid tumors by targeting αvß3 integrins and extracellular cleavage of the 7-ethyl camptothecin payload by neutrophil elastase in the tumor microenvironment. Imaging studies in the Lewis lung mouse model using an elastase cleavable quenched substrate showed pronounced elastase activity in the tumor. Pharmacokinetics studies of VIP236 in tumor-bearing mice demonstrated high stability of the SMDC in plasma and high tumor accumulation of the cleaved payload. Studies in bile-duct-cannulated rats showed that biliary excretion of the unmodified conjugate is the primary route of elimination. Treatment- and time-dependent phosphorylation of H2AX, a marker of DNA damage downstream of topoisomerase 1 inhibition, verified the on-target activity of the payload cleaved from VIP236 in vivo. Treatment with VIP236 resulted in long-lasting tumor regression in subcutaneous patient-derived xenograft (PDX) models from patients with non-small-cell lung, colon, and renal cancer as well as in two orthotopic metastatic triple-negative breast cancer PDX models. In these models, a significant reduction of brain and lung metastases also was observed.
RESUMO
To improve tumor selectivity of cytotoxic agents, we designed VIP236, a small molecule-drug conjugate consisting of an αVß3 integrin binder linked to a modified camptothecin payload (VIP126), which is released by the enzyme neutrophil elastase (NE) in the tumor microenvironment (TME). The tumor targeting and pharmacokinetics of VIP236 were studied in tumor-bearing mice by in vivo near-infrared imaging and by analyzing tumor and plasma samples. The efficacy of VIP236 was investigated in a panel of cancer cell lines in vitro, and in MX-1, NCI-H69, and SW480 murine xenograft models. Imaging studies with the αVß3 binder demonstrated efficient tumor targeting. Administration of VIP126 via VIP236 resulted in a 10-fold improvement in the tumor/plasma ratio of VIP126 compared with VIP126 administered alone. Unlike SN38, VIP126 is not a substrate of P-gp and BCRP drug transporters. VIP236 presented strong cytotoxic activity in the presence of NE. VIP236 treatment resulted in tumor regressions and very good tolerability in all in vivo models tested. VIP236 represents a novel approach for delivering a potent cytotoxic agent by utilizing αVß3 as a targeting moiety and NE in the TME to release the VIP126 payload-designed for high permeability and low efflux-directly into the tumor stroma.
RESUMO
IL3RA (CD123) is the alpha subunit of the interleukin 3 (IL-3) receptor, which regulates the proliferation, survival, and differentiation of hematopoietic cells. IL3RA is frequently expressed in acute myeloid leukemia (AML) and classical Hodgkin lymphoma (HL), presenting an opportunity to treat AML and HL with an IL3RA-directed antibody-drug conjugate (ADC). Here, we describe BAY-943 (IL3RA-ADC), a novel IL3RA-targeting ADC consisting of a humanized anti-IL3RA antibody conjugated to a potent proprietary kinesin spindle protein inhibitor (KSPi). In vitro, IL3RA-ADC showed potent and selective antiproliferative efficacy in a panel of IL3RA-expressing AML and HL cell lines. In vivo, IL3RA-ADC improved survival and reduced tumor burden in IL3RA-positive human AML cell line-derived (MOLM-13 and MV-4-11) as well as in patient-derived xenograft (PDX) models (AM7577 and AML11655) in mice. Furthermore, IL3RA-ADC induced complete tumor remission in 12 out of 13 mice in an IL3RA-positive HL cell line-derived xenograft model (HDLM-2). IL3RA-ADC was well-tolerated and showed no signs of thrombocytopenia, neutropenia, or liver toxicity in rats, or in cynomolgus monkeys when dosed up to 20 mg/kg. Overall, the preclinical results support the further development of BAY-943 as an innovative approach for the treatment of IL3RA-positive hematologic malignancies.
RESUMO
Despite the recent advances in the treatment of ovarian cancer, it remains an area of high unmet medical need. Epithelial ovarian cancer is associated with high levels of mesothelin expression, and therefore, mesothelin is an attractive candidate target for the treatment of this disease. Herein, we investigated the antitumor efficacy of the mesothelin-targeting antibody-drug conjugate (ADC) anetumab ravtansine as a novel treatment option for ovarian cancer in monotherapy and in combination with the antitumor agents pegylated liposomal doxorubicin (PLD), carboplatin, copanlisib and bevacizumab. Anetumab ravtansine showed potent antitumor activity as a monotherapy in ovarian cancer models with high mesothelin expression. No activity was seen in mesothelin-negative models. The combination of anetumab ravtansine with PLD showed additive anti-proliferative activity in vitro, which translated into improved therapeutic in vivo efficacy in ovarian cancer cell line- and patient-derived xenograft (PDX) models compared to either agents as a monotherapy. The combination of anetumab ravtansine with the PI3Kα/δ inhibitor copanlisib was additive in the OVCAR-3 and OVCAR-8 cell lines in vitro, showing increased apoptosis in response to the combination treatment. In vivo, the combination of anetumab ravtansine with copanlisib resulted in more potent antitumor activity than either of the treatments alone. Likewise, the combination of anetumab ravtansine with carboplatin or bevacizumab showed improved in vivo efficacy in the ST081 and OVCAR-3 models, respectively. All combinations were well-tolerated. Taken together, these data support the development of anetumab ravtansine for ovarian cancer treatment and highlight its suitability for combination therapy with PLD, carboplatin, copanlisib, or bevacizumab.
RESUMO
C4.4A (LYPD3) has been identified as a cancer- and metastasis-associated internalizing cell surface protein that is expressed in non-small cell lung cancer (NSCLC), with particularly high prevalence in the squamous cell carcinoma (SCC) subtype. With the exception of skin keratinocytes and esophageal endothelial cells, C4.4A expression is scarce in normal tissues, presenting an opportunity to selectively treat cancers with a C4.4A-directed antibody-drug conjugate (ADC). We have generated BAY 1129980 (C4.4A-ADC), an ADC consisting of a fully human C4.4A-targeting mAb conjugated to a novel, highly potent derivative of the microtubule-disrupting cytotoxic drug auristatin via a noncleavable alkyl hydrazide linker. In vitro, C4.4A-ADC demonstrated potent antiproliferative efficacy in cell lines endogenously expressing C4.4A and inhibited proliferation of C4.4A-transfected A549 lung cancer cells showing selectivity compared with a nontargeted control ADC. In vivo, C4.4A-ADC was efficacious in human NSCLC cell line (NCI-H292 and NCI-H322) and patient-derived xenograft (PDX) models (Lu7064, Lu7126, Lu7433, and Lu7466). C4.4A expression level correlated with in vivo efficacy, the most responsive being the models with C4.4A expression in over 50% of the cells. In the NCI-H292 NSCLC model, C4.4A-ADC demonstrated equal or superior efficacy compared to cisplatin, paclitaxel, and vinorelbine. Furthermore, an additive antitumor efficacy in combination with cisplatin was observed. Finally, a repeated dosing with C4.4A-ADC was well tolerated without changing the sensitivity to the treatment. Taken together, C4.4A-ADC is a promising therapeutic candidate for the treatment of NSCLC and other cancers expressing C4.4A. A phase I study (NCT02134197) with the C4.4A-ADC BAY 1129980 is currently ongoing. Mol Cancer Ther; 16(5); 893-904. ©2017 AACR.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Moléculas de Adesão Celular/imunologia , Imunoconjugados/administração & dosagem , Aminobenzoatos/química , Aminobenzoatos/imunologia , Animais , Anticorpos Monoclonais/imunologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Moléculas de Adesão Celular/antagonistas & inibidores , Linhagem Celular Tumoral , Cisplatino/administração & dosagem , Cisplatino/imunologia , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/imunologia , Humanos , Imunoconjugados/química , Imunoconjugados/imunologia , Camundongos , Oligopeptídeos/química , Oligopeptídeos/imunologia , Paclitaxel/administração & dosagem , Paclitaxel/imunologia , Vimblastina/administração & dosagem , Vimblastina/análogos & derivados , Vimblastina/imunologia , Vinorelbina , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The fibroblast growth factor receptor FGFR2 is overexpressed in a variety of solid tumors, including breast, gastric, and ovarian tumors, where it offers a potential therapeutic target. In this study, we present evidence of the preclinical efficacy of BAY 1187982, a novel antibody-drug conjugate (ADC). It consists of a fully human FGFR2 monoclonal antibody (mAb BAY 1179470), which binds to the FGFR2 isoforms FGFR2-IIIb and FGFR2-IIIc, conjugated through a noncleavable linker to a novel derivative of the microtubule-disrupting cytotoxic drug auristatin (FGFR2-ADC). In FGFR2-expressing cancer cell lines, this FGFR2-ADC exhibited potency in the low nanomolar to subnanomolar range and was more than 100-fold selective against FGFR2-negative cell lines. High expression levels of FGFR2 in cells correlated with efficient internalization, efficacy, and cytotoxic effects in vitro Pharmacokinetic analyses in mice bearing FGFR2-positive NCI-H716 tumors indicated that the toxophore metabolite of FGFR2-ADC was enriched more than 30-fold in tumors compared with healthy tissues. Efficacy studies demonstrated that FGFR2-ADC treatment leads to a significant tumor growth inhibition or tumor regression of cell line-based or patient-derived xenograft models of human gastric or breast cancer. Furthermore, FGFR2 amplification or mRNA overexpression predicted high efficacy in both of these types of in vivo model systems. Taken together, our results strongly support the clinical evaluation of BAY 1187982 in cancer patients and a phase I study (NCT02368951) has been initiated. Cancer Res; 76(21); 6331-9. ©2016 AACR.
Assuntos
Aminobenzoatos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Imunoconjugados/uso terapêutico , Neoplasias/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/análise , Animais , Anticorpos Monoclonais Humanizados , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Human antibody-ribonuclease (RNase) fusion proteins, referred to as immunoRNases, have been proposed as an alternative to heterologous immunotoxins, without their immunogenicity and unspecific toxicity issues. In this study, we investigated if human pancreatic RNase will be suitable as effector component in a therapeutic antibody development platform. We generated several fusion proteins consisting of tumor-specific human immunoglobulins (IgGs) and human pancreatic RNase. Transient mammalian cell production was efficient and IgG-RNases were purified to homogeneity. Antigen binding was comparable to the parental antibodies and RNase catalytic activity was retained even in the presence of 50-fold molar excess of human cytosolic RNase inhibitor (RI). Serum stability, cell binding and internalization of IgG-RNases were comparable to the parental IgGs. Despite these promising properties, none of the IgG-RNases revealed significant inhibition of tumor cell growth in vitro even when targeting different antigens putatively employing different endocytotic pathways. The introduction of different linkers containing endosomal protease cleavage sites into the IgG-RNase did not enhance cytotoxicity. Similarly, RI evasive human pancreatic RNase variants mediated only small inhibiting effects on tumor cell growth at high concentrations, potentially reflecting inefficient cytosolic translocation. Taken together, human pancreatic RNase and variants did not prove to be generally suitable as effector component for a therapeutic antibody drug development platform.
Assuntos
Adenocarcinoma/tratamento farmacológico , Anticorpos Catalíticos/metabolismo , Neoplasias do Colo/tratamento farmacológico , Imunoglobulina G/metabolismo , Imunoterapia/métodos , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Recombinantes de Fusão/metabolismo , Ribonucleases/metabolismo , Adenocarcinoma/imunologia , Anticorpos Catalíticos/genética , Antígenos de Neoplasias/imunologia , Processos de Crescimento Celular/efeitos dos fármacos , Neoplasias do Colo/imunologia , Citotoxicidade Imunológica , Endocitose , Células HEK293 , Células HT29 , Humanos , Imunoglobulina G/genética , Imunoterapia/tendências , Neoplasias Pulmonares/imunologia , Terapia de Alvo Molecular , Pâncreas/enzimologia , Proteínas Recombinantes de Fusão/genética , Ribonucleases/genéticaRESUMO
Mesothelin is a tumor differentiation antigen frequently overexpressed in tumors such as mesothelioma, ovarian, pancreatic, and lung adenocarcinomas while showing limited expression in nonmalignant tissues. Mesothelin is therefore an attractive target for cancer therapy using antibody-drug conjugates (ADC). This study describes the detailed characterization of anetumab ravtansine, here referred to as BAY 94-9343, a novel ADC consisting of a human anti-mesothelin antibody conjugated to the maytansinoid tubulin inhibitor DM4 via a disulfide-containing linker. Binding properties of the anti-mesothelin antibody were analyzed using surface plasmon resonance, immunohistochemistry, flow cytometry, and fluorescence microscopy. Effects of BAY 94-9343 on cell proliferation were first studied in vitro and subsequently in vivo using subcutaneous, orthotopic, and patient-derived xenograft tumor models. The antibody binds to human mesothelin with high affinity and selectivity, thereby inducing efficient antigen internalization. In vitro, BAY 94-9343 demonstrated potent and selective cytotoxicity of mesothelin-expressing cells with an IC(50) of 0.72 nmol/L, without affecting mesothelin-negative or nonproliferating cells. In vivo, BAY 94-9343 localized specifically to mesothelin-positive tumors and inhibited tumor growth in both subcutaneous and orthotopic xenograft models. In addition, BAY 94-9343 was able to induce a bystander effect on neighboring mesothelin-negative tumor cells. Antitumor efficacy of BAY 94-9343 correlated with the amount of mesothelin expressed and was generally superior to that of standard-of-care regimen resulting in complete tumor eradication in most of the models. BAY 94-9343 is a selective and highly potent ADC, and our data support its development for the treatment of patients with mesothelin-expressing tumors.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Proteínas Ligadas por GPI/imunologia , Imunoconjugados/administração & dosagem , Maitansina/análogos & derivados , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Anticorpos Monoclonais/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Efeito Espectador , Linhagem Celular Tumoral , Proteínas Ligadas por GPI/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Maitansina/administração & dosagem , Mesotelina , Neoplasias/imunologia , Neoplasias/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Vitronectin receptor (alpha(V)beta(3)) antagonists have been implicated as a possible new treatment of restenosis following balloon angioplasty. In this work we investigate a series of novel arginine mimetic scaffolds leading to new insight of the alpha(V)beta(3)/ligand interaction. Squaric acid amide 10 is a subnanomolar alpha(V)beta(3) antagonist with improved potency on human smooth muscle cell migration.
Assuntos
Compostos de Bifenilo/farmacologia , Ciclobutanos/farmacologia , Receptores de Vitronectina/antagonistas & inibidores , Sulfonamidas/farmacologia , Sítios de Ligação/efeitos dos fármacos , Compostos de Bifenilo/química , Ciclobutanos/química , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Estrutura Terciária de Proteína , Receptores de Vitronectina/química , Relação Estrutura-Atividade , Sulfonamidas/químicaRESUMO
OBJECTIVE: To evaluate the potential of sildenafil, vardenafil and tadalafil, all phosphodiesterase-5 (PDE-5) inhibitors used for treating erectile dysfunction, for treating benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). MATERIALS AND METHODS: The mRNA expression of the PDE-5 was determined in rat LUT tissues. The PDE-5 inhibitors were also tested in organ-bath experiments and in a partial bladder outlet obstruction (BOO) rat model in vivo. RESULTS: The highest PDE-5 mRNA expression was in the bladder, followed by the urethra and prostate. PDE-5 inhibitors dose-dependently reduced the contraction of the isolated bladder, urethral and prostate strips. The rank order of potency was vardenafil > sildenafil > tadalafil. In human prostate stromal cells vardenafil inhibited cell proliferation and was more effective than tadalafil and sildenafil. In the BOO model, there was a reduction in the non-voiding contractions after bolus intravenous administration of 3 mg/kg sildenafil and vardenafil. CONCLUSION: These results show that PDE-5 is expressed in LUT tissues. PDE-5 inhibitors induced significant relaxation of these tissues, inhibited the proliferation of human prostate stromal cells and reduced the irritative symptoms of BPH/LUTS in vivo. Therefore, PDE-5 inhibitors could be used as an effective treatment for BPH/LUTS.
Assuntos
3',5'-GMP Cíclico Fosfodiesterases/antagonistas & inibidores , Inibidores de Fosfodiesterase/uso terapêutico , Hiperplasia Prostática/tratamento farmacológico , Prostatismo/tratamento farmacológico , 3',5'-GMP Cíclico Fosfodiesterases/metabolismo , Animais , Carbolinas/uso terapêutico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5 , Imidazóis/uso terapêutico , Masculino , Piperazinas/uso terapêutico , Hiperplasia Prostática/complicações , Prostatismo/etiologia , Purinas , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Citrato de Sildenafila , Sulfonas/uso terapêutico , Tadalafila , Resultado do Tratamento , Triazinas/uso terapêutico , Dicloridrato de VardenafilaRESUMO
Vitronectin receptor (alpha(V)beta(3)) antagonism has been implicated as a mechanism for the treatment of restenosis following balloon angioplasty. In this work we present results from screening of a focused combinatorial library based on a biphenyl moiety. Our SAR studies led to the identification of compounds with subnanomolar activity, selectivity towards the related GPIIbIIIa receptor and functional activity on human smooth muscle cell migration.
Assuntos
Compostos de Bifenilo/farmacologia , Receptores de Vitronectina/antagonistas & inibidores , Compostos de Bifenilo/química , Técnicas de Química Combinatória , Relação Estrutura-AtividadeRESUMO
Vitronectin receptor (alpha(V)beta(3)) antagonism has been implicated in a variety of disease states, like restenosis, osteoporosis and cancer. In this work, we present the development of a novel class of biphenyl vitronectin receptor antagonists. Identified from a focused combinatorial library based on para-bromo phenylalanine, these compounds show nanomolar affinity to the vitronectin receptor and display unprecedented SAR. Their binding mode can be rationalized by computational docking studies using the X-ray structure of alpha(V)beta(3).